Silver has a very strong catalytx effect on the peroxodisulphate oxidation of Brilliant Cresyl Blue in the presence of 1,lO-Phenanthroline as an activator. The reaction was followed spectrophotomemcally by measuring the rate of change in absorbance of brilliant cresyl blue at 635 nm and 30OC. Silver can be determined in the range of 0.3 - 1500.0 ng/d by a fixed time method. The limit of detection is about 0.1 nghnl of silver. Silver in real samples was determined with satisfactory results.
